This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Kinases are a group of enzymes which serve as crucial nodes in cell signaling network. It has been demonstrated that cancers may be resulted from the over expression of certain kinases. Many drugs based on kinase inhibitors are already on the market or in clinical development for cancer treatment. The analysis of the human genome has yielded a large library of (over 500) protein kinases. It is important to develop new technologies for quick high-throughput screening of protein kinase inhibitors. Here we propose the development of a low-cost, multiplex, label-free, and ultrasensitive technique for kinase profiling using a nanoelectronic chip based on nanoelectrode arrays (NEAs). Individually addressed NEAs are fabricated using vertically aligned carbon nanotubes (CNTs) inlaid in SiO2 with only the very end exposed which are further functionalized with proper peptide substrates and enclosed in a microfluidic channel. In the presence of kinases and ATP, the corresponding peptide substrates undergo phosphorylation with the introduction of a negatively charged phosphate group, resulting in a change in the AC impedance of the NEA. The rate of the change is associated with the kinase activity and concentration. This technique could potentially enable the simultaneous detection of up to 100 peptide substrates responding to the mixture of kinases at 1-100 pM in ~5-10 microliter solutions. This will significantly expedite kinase profiling for cancer diagnosis, treatment monitoring, and drug discovery.